Dan Snow, an archaeologist, and Dr Sarah Parcak, a space archaeologist, team up to discover the lost Vikings of America. Sarah uses satellite technology to spot ruins buried beneath the surface, as small as 30cm deep. Dan explores how these Vikings sailed thousands of miles across open water when most ships never set foot on land. He also tracks their expansion westward, starting as raiders and then as settlers and traders throughout Britain and beyond to Iceland and Greenland. In North America, they uncover what could be the most westerly Viking settlement ever discovered.